Devices able to generate millimeter waves are known in the art.
For instance, negative resistance devices such as Gunn diodes and Trapatt and Impatt devices are known.
In such devices, as the usage frequency increases, the generated electromagnetic signal has progressively decreasing power and progressively broadened frequency band or emission line, so that such devices are unusable for millimeter waves corresponding to frequencies equal to or greater than 60 GHz.
Also known in the prior art are devices able to transmit millimeter waves that do not suffer from the aforementioned problem.
For instance, U.S. Pat. No. 5,998,781 discloses an opto-electronic integrated circuit or OEIC for generating and transmitting millimeter waves, comprising a ring laser circuit able to generate optical pulses and a photo-diode able to convert the optical pulses into electromagnetic waves whose frequency corresponds to millimeter waves.The known OEIC device, however, is only an oscillator device and therefore it cannot be used to transmit information.In particular, the known device cannot modulate the optical carrier with information constituted, for instance, by voice and/or data, and transmit the corresponding modulated electromagnetic signal.
Moreover, the aforementioned patent does not provide any indication for making OEIC devices able to receive the modulated electromagnetic signal and to extract, by demodulation, the information contained therein.